Development of a low-level (37)Ar calibration standard.

Abstract Argon-37 is an environmental signature of an underground nuclear explosion. Producing and quantifying low-level 37 Ar standards is an important step in the development of sensitive field measurement instruments. This paper describes progress at Pacific Northwest National Laboratory in developing a process to generate and quantify low-level 37 Ar standards, which can be used to calibrate sensitive field systems at activities consistent with soil background levels. This paper presents a discussion of the measurement analysis, along with assumptions and uncertainty estimates.